Altimetry measurements are acquired by an altimeter on a non-synchronous satellite in a repeating low-Earth orbit designed to ﬂy over the same points at regular intervals.
The ocean climate has traditionally been monitoring with measurements from ships. Research vessels, advanced instruments and skilled technical personnel are then needed to acquire high quality data.
Three fully autonomous Terma HE-5AS Star Trackers provide the precise pointing knowledge required for the main instrument, the SIRAL interferometer, on-board the CryoSat satellite. All three Star Trackers are mounted directly on the payload antenna bench of the CryoSat satellite for optimized structural stability between the star sensors and the payload sensors measuring frames.
Two types of satellite earth observation sensors are particularly interesting for monitoring the polar environment: Synthetic Aperture Radar and Radar Altimetry.
Only a few meteorological observation series in the high Arctic are available during the last 100 years. Fortunately one of those series is located on Spitsbergen.
The Intergovernmental Panel on Climate Change (IPCC) concluded in 2001 that man-made emissions of so-called “greenhouse gases” most likely are leading to global warming, and that the temperature incrase probably will be at maximum at high northern latitudes.
Professor Ola M. Johannessen Nansen Environment and Remote Sensing Center
As a member of the European Space Agency, ESA, the Norwegian Space Centre started potential participant activities in the ENVISAT-programme in 1991. On behalf of Norway the ENVISAT declaration was signed in 1992. The Norwegian Space Centre has worked with the ENVISAT programme for more than ten years, and Norway has through the Norwegian Space Centre paid approx. 200 MNOK for the participation in the ENVISAT programme since the start.
Space-based maritime monitoring and surveillance has been a focus area for the Norwegian Defence Research Establishment (FFI) for over a decade. Throughout the ERS and RADARSAT-1 era, FFI has performed applied research that helped establish today’s operational services for radar satellite-based oil spill and fisheries monitoring in Norway.
Microwaves, not sensitive to cloud cover or sun illumination, are important for remote sensing at Nordic latitudes. The Arctic ice cover and the boreal forests are extensive areas important for the living conditions and sensitive to climate changes at these latitudes. ENVISAT offers new possibilities to detect and follow possible changes e.g. due to the greenhouse effect.